Sight and smell tests offer key to dementia diagnosis

Simple sight and smell tests could be used to spot dementia years before sufferers experience memory symptoms, new research suggests.

Researchers at Moorfields Eye Hospital and the UCL Institute of Ophthalmology found a link between poor cognitive ability — a “clear warning sign” of the early stages of Alzheimer’s — and the thickness of people’s retinal nerves.

In a trial of 33,000 participants who had tests on memory, reaction time and reasoning, eye scans showed the nerve fibre layer was “significantly thinner” among those who performed poorly on cognitive tests.